Field of the Invention
This disclosure relates to a method of manufacturing a liquid discharge head in which a device substrate having an energy generating element is positioned on and fixed to a supporting member with an adhesive agent.
Description of the Related Art
An ink jet printhead configured to discharge ink as a liquid includes a printing device substrate having a heater for discharging ink and a supporting member configured to support a printing device substrate. The printing device substrate includes a supply port through which ink is supplied. The supporting member includes a supply passage configured to supply ink to the supply port of the printing device substrate.
In an ink jet printhead of this type, an end surface of a wall which forms the supply port of the printing device substrate is fixed to an end surface of a wall which forms the supply passage of the supporting member with an adhesive agent. A method of manufacturing the inkjet printhead includes a step of applying an adhesive agent onto the end surface of the wall of the supply passage, and a step of positioning the printing device substrate with respect to the supporting member and bonding the wall of the supply port and the wall of the supply passage with an adhesive agent.
In the related art, when the printing device substrate is positioned relative to and fixed to the supporting member with an adhesive agent, the following fixing method as described below is employed. Japanese Patent Laid-Open No. 2009-298108 discloses a method in which a supporting member to which an adhesive agent is applied is positioned with respect to a positioning device or a jig, and then the printing device substrate is positioned at a predetermined position with reference to the positioning device or the jig to which the supporting member is positioned, thereby sticking the printing device substrate to the supporting member.
However, in the method of the related art, there is a problem as described below.
FIG. 6 shows a positional relationship between a wall which forms a supply port of a printing device substrate and a wall which forms a supply passage of the supporting member in a case where variations occur in dimensional accuracy of the supporting member in a method of fixing the printing device substrate and the supporting member of the related art.
As illustrated in FIG. 6, a wall 111a of a supply port 111 of a printing device substrate 106 having an energy generating element and a wall 112a of a supply passage 112 of a supporting member 107 are fixed to each other with an adhesive agent 113. In association with a reduction in size of the printing device substrate 106, securement of the required molding accuracy or machining accuracy has become difficult. Therefore, the position of the supply passage 112 of the supporting member 107 may vary in terms of positional accuracy with respect to a reference position of the supporting member 107.
In the case described above, as illustrated in FIG. 6, relative positioning of the wall 111a of the supply port 111 of the printing device substrate 106 and the wall 112a of the supply passage 112 of the supporting member 107 may be shifted from each other. In such a case, since the adhesive agent 113 is applied onto an end surface 112b of the wall 112a of the supply passage 112, center positions of the wall 111a of the supply port 111 and the wall 112a of the supply passage 112 in the thickness direction of the walls 111a and 112a are shifted from each other as illustrated in FIG. 6.
When an end surface 111b of the wall 111a of the supply port 111 is brought toward the end surface 112b of the wall 112a of the supply passage 112 and stuck thereto in such a shifted state, the adhesive agent 113 is not likely to be flattened out evenly on both sides of the wall 111a of the supply port 111 of the printing device substrate 106 in the thickness direction. Therefore, as illustrated in FIG. 6, the adhesive agent 113 is not adhered to both side surfaces (wall surfaces) 111c of the wall 111a of the supply port 111, but is adhered only to one of the side surfaces 111c of the wall 111a. 
In a case where the wall 111a of the supply port 111 is fixed to the wall 112a of the supply passage 112 in the state described above, an adhesion strength between the wall 111a of the supply port 111 and the wall 112a of the supply passage 112 is weak. Therefore, when deformation or the like occurs in the supporting member 107, since the adhesion strength between the walls 111a and 112a is weak, an adhered portion is separated, and hence ink may enter from the supply port 111 from a space adjacent thereto.
When such a state occurs, in an ink jet printhead provided with a plurality of types of ink in different colors, ink enters the supply port 111 and is mixed in the supply port 111 adjacent thereto with the wall 111a of the supply port 111 interposed therebetween, and the quality of a printed result is significantly reduced.
This disclosure provides a method of manufacturing a liquid discharge head that maintains a state in which a wall of a supply port is adhered to a wall of a supply passage stably even though positions of the wall of the supply port and the wall of the supply passage are displaced from each other.